For testing and troubleshooting purposes, telephone network field service personnel, or craftspersons, have conventionally employed what are essentially ruggedized versions of a standard telephone handset. As such, the functional capabilities of these conventional test sets are not adequate to handle an ever expanding number of aspects of today's telecommunication environment, including, but not limited to, special features, such as call-waiting, caller ID, and the use of POTS (plain old telephone service) lines to deliver digital data services. In addition, because the acoustic interface of a conventional test set is essentially a half-duplex architecture, the field technician's ability to use it in a `hands-free` manner can be severely limited, especially in an environment having high ambient noise, such as that inherent in the operation of industrial equipment and the flow of highway traffic.
As a consequence, there is a need for an improved test set, which retains the capabilities and physical characteristics of a conventional test set (namely, one that can test POTS lines, and is relatively compact (hand held) and physically and electrically robust), yet enables the craftsperson to monitor, receive and process signals of a variety of formats that may be present on a line under test. Moreover, field personnel have expressed a desire that their test sets have a truly `hands-free`, full-duplex, dual direction acoustic interface or speakerphone, namely, one that allows the field technician to talk (from a distance) in the presence of background noise, while simultaneously listening to an acoustic output being generated by the test set's receiver.